In videos posted online this week, He said he used a gene-editing technology known as CRISPR-Cas9 to alter the embryonic genes of twin girls born this month.

A Chinese scientist at the centre of a controversy over what he claims are the world’s first genetically edited children apologised on Wednesday for the result being leaked unexpectedly.(AP)

A Chinese scientist at the centre of a controversy over what he claims are the world’s first genetically edited children apologised on Wednesday for the result being leaked unexpectedly as he detailed his findings at a conference in Hong Kong.

He Jiankui, an associate professor at Southern University of Science and Technology in Shenzhen, China, addressed a packed hall of around 700 people attending the Human Genome Editing Summit at the University of Hong Kong.

“First, I must apologise that this result was leaked unexpectedly. This study has been submitted to a scientific journal for review,” He said. He did not name the journal and said his university was unaware of his study.

In videos posted online this week, He said he used a gene-editing technology known as CRISPR-Cas9 to alter the embryonic genes of twin girls born this month.

He defended the work, saying gene editing would help protect the girls from infection with HIV, the virus that causes AIDS.

But scientists and the Chinese government have denounced the work that He said he carried out, and a hospital linked to his research suggested its ethical approval had been forged. [

The conference moderator, Robin Lovell-Badge, said the summit organisers were unaware of the story until it broke this week.

CRISPR-Cas9 is a technology that allows scientists to essentially cut and paste DNA, raising hope of genetic fixes for disease. However, there are concerns about safety and ethics.

More than 100 scientists, most in China, said in an open letter on Tuesday the use of CRISPR-Cas9 technology to edit the genes of human embryos was dangerous and unjustified. “Pandora’s box has been opened,” they said.

He’s research focuses on genome sequencing technology, bioinformatics and genome editing, according to his biography on the summit’s website.

He received his PhD at Rice University in Houston, Texas, and worked as a postdoctoral research fellow in Stephen Quake lab at Stanford University according to the site.